On my team we had a claymore that we took the C-4 out of and used for training. We once took it with us on a counter-terrorism training mission and used it on some MP's. We ran a few wires out of the fuze wells and placed it where the MP's would see it.
It worked like a charm, stopped them dead in their tracks, they made an emergeny call to us and said, "Please tell us it's not real....."